/* Blob.js
 * A Blob implementation.
 * 2014-05-27
 * 
 * By Eli Grey, http://eligrey.com
 * By Devin Samarin, https://github.com/eboyjr
 * License: X11/MIT
 *   See LICENSE.md
 */

/*global self, unescape */
/*jslint bitwise: true, regexp: true, confusion: true, es5: true, vars: true, white: true,
  plusplus: true */

/*! @source http://purl.eligrey.com/github/Blob.js/blob/master/Blob.js */

/* Baturu改进版, 支持cmd、amd、commonjs、Worker、window版本等 */
; (function (root, name, definition) {
	var hasDefine = typeof define === 'function',
		hasExports = typeof module !== 'undefined' && module.exports;
	if (hasDefine) {
		define(definition);
	} else if (hasExports) {
		module.exports = definition();
	} else {
		root[name] = definition();
	}
})(typeof self !== "undefined" && self
|| typeof window !== "undefined" && window
|| this.content || this,
	'Blob', function () {
		return (function (view) {
			"use strict";
			view.URL = view.URL || view.webkitURL;

			if (view.Blob && view.URL) {
				try {
					new Blob;
					return Blob;
				} catch (e) { }
			}

			// Internally we use a BlobBuilder implementation to base Blob off of
			// in order to support older browsers that only have BlobBuilder
			var BlobBuilder = view.BlobBuilder || view.WebKitBlobBuilder || view.MozBlobBuilder || (function () {
				var
					get_class = function (object) {
						return Object.prototype.toString.call(object).match(/^\[object\s(.*)\]$/)[1];
					}
					, FakeBlobBuilder = function BlobBuilder() {
						this.data = [];
					}
					, FakeBlob = function Blob(data, type, encoding) {
						this.data = data;
						this.size = data.length;
						this.type = type;
						this.encoding = encoding;
					}
					, FBB_proto = FakeBlobBuilder.prototype
					, FB_proto = FakeBlob.prototype
					, FileReaderSync = view.FileReaderSync
					, FileException = function (type) {
						this.code = this[this.name = type];
					}
					, file_ex_codes = (
						"NOT_FOUND_ERR SECURITY_ERR ABORT_ERR NOT_READABLE_ERR ENCODING_ERR "
						+ "NO_MODIFICATION_ALLOWED_ERR INVALID_STATE_ERR SYNTAX_ERR"
					).split(" ")
					, file_ex_code = file_ex_codes.length
					, real_URL = view.URL || view.webkitURL || view
					, real_create_object_URL = real_URL.createObjectURL
					, real_revoke_object_URL = real_URL.revokeObjectURL
					, URL = real_URL
					, btoa = view.btoa
					, atob = view.atob

					, ArrayBuffer = view.ArrayBuffer
					, Uint8Array = view.Uint8Array
					;
				FakeBlob.fake = FB_proto.fake = true;
				while (file_ex_code--) {
					FileException.prototype[file_ex_codes[file_ex_code]] = file_ex_code + 1;
				}
				if (!real_URL.createObjectURL) {
					URL = view.URL = {};
				}
				URL.createObjectURL = function (blob) {
					var
						type = blob.type
						, data_URI_header
						;
					if (type === null) {
						type = "application/octet-stream";
					}
					if (blob instanceof FakeBlob) {
						data_URI_header = "data:" + type;
						if (blob.encoding === "base64") {
							return data_URI_header + ";base64," + blob.data;
						} else if (blob.encoding === "URI") {
							return data_URI_header + "," + decodeURIComponent(blob.data);
						} if (btoa) {
							return data_URI_header + ";base64," + btoa(blob.data);
						} else {
							return data_URI_header + "," + encodeURIComponent(blob.data);
						}
					} else if (real_create_object_URL) {
						return real_create_object_URL.call(real_URL, blob);
					}
				};
				URL.revokeObjectURL = function (object_URL) {
					if (object_URL.substring(0, 5) !== "data:" && real_revoke_object_URL) {
						real_revoke_object_URL.call(real_URL, object_URL);
					}
				};
				FBB_proto.append = function (data/*, endings*/) {
					var bb = this.data;
					// decode data to a binary string
					if (Uint8Array && (data instanceof ArrayBuffer || data instanceof Uint8Array)) {
						var
							str = ""
							, buf = new Uint8Array(data)
							, i = 0
							, buf_len = buf.length
							;
						for (; i < buf_len; i++) {
							str += String.fromCharCode(buf[i]);
						}
						bb.push(str);
					} else if (get_class(data) === "Blob" || get_class(data) === "File") {
						if (FileReaderSync) {
							var fr = new FileReaderSync;
							bb.push(fr.readAsBinaryString(data));
						} else {
							// async FileReader won't work as BlobBuilder is sync
							throw new FileException("NOT_READABLE_ERR");
						}
					} else if (data instanceof FakeBlob) {
						if (data.encoding === "base64" && atob) {
							bb.push(atob(data.data));
						} else if (data.encoding === "URI") {
							bb.push(decodeURIComponent(data.data));
						} else if (data.encoding === "raw") {
							bb.push(data.data);
						}
					} else {
						if (typeof data !== "string") {
							data += ""; // convert unsupported types to strings
						}
						// decode UTF-16 to binary string
						bb.push(unescape(encodeURIComponent(data)));
					}
				};
				FBB_proto.getBlob = function (type) {
					if (!arguments.length) {
						type = null;
					}
					return new FakeBlob(this.data.join(""), type, "raw");
				};
				FBB_proto.toString = function () {
					return "[object BlobBuilder]";
				};
				FB_proto.slice = function (start, end, type) {
					var args = arguments.length;
					if (args < 3) {
						type = null;
					}
					return new FakeBlob(
						this.data.slice(start, args > 1 ? end : this.data.length)
						, type
						, this.encoding
					);
				};
				FB_proto.toString = function () {
					return "[object Blob]";
				};
				FB_proto.close = function () {
					this.size = this.data.length = 0;
				};
				return FakeBlobBuilder;
			}());

			return function Blob(blobParts, options) {
				var type = options ? (options.type || "") : "";
				var builder = new BlobBuilder();
				if (blobParts) {
					for (var i = 0, len = blobParts.length; i < len; i++) {
						builder.append(blobParts[i]);
					}
				}
				return builder.getBlob(type);
			};

		}(typeof self !== "undefined" && self || typeof window !== "undefined" && window || this.content || this));
	});